Most people understand that mowing is a key aspect of the annual lawn care cycle, and when it comes to cutting grass, timing is critical. To help you get it right and achieve the best results, here’s our guide to when to mow the lawn & 7 tips for how to do it.
If you want a preview of some of the stuff we’re going to be talking about – as well as a few extra tips and hints – you can also check out this video before reading on.
Factors affecting your lawn-mowing schedule
Before we start talking about when to mow the lawn, it’s important to understand that your yearly mowing schedule depends largely on two things: the part of the UK where you live and the weather of any particular year.
First, there can be a big difference between the seasons and weather on the south coast of England and the northern parts of Scotland.
Spring arrives earlier in the south and winter arrives later, so when those in the warmer parts of the country are dusting off their mowers to begin their annual grass care regime, those living further north will still have a few more weeks to wait.
This means you have to rely on cues from the weather where you live to tell you when to start mowing, rather than trying to stick to some kind of rigid UK-wide mowing calendar.
Similarly, weather from one year to the next can vary. This has always been the case, but with global weather systems currently in flux, the seasons are now even more unpredictable than ever.
Even if you start mowing on 1st April one year, it doesn’t necessarily follow that you should start mowing on 1st April the following year. Again, you need to look out for the cues that nature provides to guide you in your annual lawn-mowing regime.
Bearing this in mind, now let’s move on to look at when you should mow your lawn – and how your mowing should vary throughout the year.
The annual mowing cycle
March or April – first cut of the year
Throughout the winter, your lawn will be mostly dormant, growing very little. The first growth of spring usually begins some time in March or early April, and this is when you should plan to give your grass its first mow of the year.
When you notice your grass has started growing, choose a dry day and give your lawn its first trim. For this first cut, don’t be tempted to take off too much – using your mower’s highest setting is recommended.
After the first cut, the temperatures should continue to rise, stimulating further growth. Keep an eye on your grass to judge when to mow it again, but at this time of year, you can expect it to need cutting around once every two weeks or so, although perhaps less.
Moving from April into May and then June, weather conditions will usually provide the perfect combination of rain and sun that results in this being one of the strongest growth periods of the year.
You will find you may need to cut the lawn as frequently as every ten days or even every week; as always, keep an eye on how quickly your grass is growing and use this to guide your judgement.
In the UK, as far as grass is concerned, July and August can be the most unpredictable months of the year. They can bring dry weather, hot and dry weather or wet weather – and this can significantly affect how often you need to mow your lawn.
If there is less rainfall, growth will slow again, and you won’t need to mow your lawn as often as in May and June; perhaps once every two weeks will be enough.
If increased temperatures accompany the dry weather, you will also be able to reduce your frequency to around once every two weeks or less, but you should also avoid cutting the grass too short. This will give it a better chance of surviving the more challenging conditions.
On the other hand, if you are facing a wetter summer, your lawn will continue growing strongly throughout, and you will need to keep cutting as often as in the previous months, perhaps as much as once a week.
With the arrival of September, things become more predictable again, with the return of the cooler weather and, usually, increased rainfall. This is another major growing season for grass in the UK, so expect to be cutting your lawn up to once a week again in September.
By the start of October, autumn is well on the way, and with the cooler weather, growth begins to slow again.
You may need to cut your lawn once or twice in October, and although you will still need to cut your lawn a couple of times throughout the winter, this represents the end of you regular mowing schedule.
If it hasn’t already happened in October, November will usually bring the first frosts of the year. Your main job in November will be to clear twigs and leaves from your lawn, but you should also be prepared to give your lawn one last trim before the winter truly sets in.
Lawn growth will be minimal from December to March, but you may occasionally need to give it a light trim to keep it looking tidy.
With the changing climate and mild winters we are now experiencing, this is especially true, and winter mowing may become more common in the years to come.
When mowing during the winter, never mow grass that’s covered in frost; the cold conditions weaken the grass, and mowing at this time can damage it. Mowing while the ground is frozen can also compact the soil.
For similar reasons, you should avoid mowing your lawn when frost is forecast in the next 24 hours.
What time of day should you cut your lawn?
As well as knowing when to cut the lawn during the year, it’s also important to understand the best time of day for mowing.
The optimum time is generally accepted as being mid-morning. This is because any dew will have had time to evaporate off, leaving your grass dry, but it will also have plenty of time to recover before nightfall.
However, during cooler parts of the year, dew may still be present even in mid-morning, so it may be better to wait.
Early to mid-afternoon is probably the second-best choice. This is after the most intense heat of the midday sun has passed, but the grass still has time to recover before nighttime.
That said, for much of the year in the UK, the sun is unlikely to be too intense, even during the hottest part of the day – with the exception of the middle of summer – so mowing your lawn around midday can also be acceptable.
The worst times of day to cut your lawn are early morning and late afternoon/early evening.
In the morning, grass may still be moist from dew, and cutting it when wet will leave it susceptible to disease. Wet grass will also interfere with your mower’s blades, causing them to tear rather than cut the grass, and this will damage and weaken the plants.
Cutting in the later afternoon or early evening doesn’t leave the grass enough time to recover before nightfall, and when the sun goes down and dew begins to form, it will be left vulnerable to disease.
Pro mowing tips to help your lawn stay healthy
1. Always follow the ‘one-third’ rule
The first golden rule of lawn mowing is the ‘one-third’ rule. You should never take off more than one-third of your grass’s height in one go since doing so will place it under too much stress.
Instead, if you want to cut it short, do so gradually, each time cutting it a little shorter than before – but never taking off more than one-third each time.
2. Always ensure your blades are sharp
The second golden rule is to ensure your blades are always sharp. Blunt blades tear grass rather than cut it, and this causes significant stress and damage to the plants. Using sharp blades will allow the grass to recover more quickly, keeping it safe from disease and pests.
3. Avoid cutting lawn when it is wet or covered in frost
Avoid cutting grass when it is wet or frosty since this leaves it weakened and susceptible to disease. There is also a risk of compacting the soil if mowing in these conditions.
Having said that, here’s a short video about cutting wet grass.
4. Be careful when turning your mower during winter
Be careful when turning your mower when cutting in winter since the wheels can damage your turf.
5. Check your lawn for debris before the first cut of spring
Before your first cut in spring, check the grass for debris like twigs, stones, kids’ toys and so on. They may be hidden in the longer grass and will damage your blades if you run over them.
6. Avoid cutting too close if your lawn is susceptible to moss
If your lawn is susceptible to moss, resist the temptation to cut it too short – otherwise, you are inviting more moss to move in.
7. Keep up your mowing schedule
Never let your lawn get out of control but rather, keep an eye on it and keep it mown as necessary. This will help it remain healthy and in a good state, and a healthy lawn is better able to defend itself against all kinds of pests and disease, making lawn care easier in the long run.
Here’s an interesting video about tackling a lawn that’s been left to get out of hand.
Keep on top of it – and follow the cues from nature
When it comes to mowing your lawn, perhaps the best thing is to be flexible. Follow the cues from nature rather than trying to stick to a rigid schedule – and as long as you keep on top of it, mowing your lawn should be something to enjoy rather than dread.